Lamp for matching colors by artificial light.



M. WEERTZ. LAMP FOR MATCHING COLORS BY ARTIFIGIAL LIGHT, APPLICATIONFILED MAY 27, 1911.

1,015,721; Patented Jan. 23, 1912.

WITNESSES INVENTSS onmon.

MAX WEERTZ, OF BRADFORD, ENGLAND.

Specification of Letters Patent.

Application filed May fl'i, 1911.

Patented Jan. 23, 1912.. Serial n6. 630,430.

To all whom it may concern:

Be it known that 1, MAX Wnnn'rz, a sub- .ject of the Emperor of Germany,residing at Bradford, Yorkshire, England, have invented certain new anduseful Improvements in Lamps for Matching Colors by Ar tificial Light;and I do hereby declare the following to be a full, clear, and exactdescription of the invention, such as will enable others skilled in theart to which it appertains to make and use the same.

This invention relates to an. improved daylight lamp, that is to say, alamp which enables the colors of materials to be matched by. artificiallight, the lamps being so arranged as to modify the artificial light asto cause it to give the same eflect as daylight.

The object of the invention is to provide a cheap lamp which shall besimple in its .construction and use, which shall be constant in thequality and quantity of the light it gives out, and which shall becapable of use with readily accessible means such as incandescentelectric lamps or incandescent gas or'petroleum lamps.

ln the accompanying drawing a lamp constructed in accordance with thepresent invention is shown which lamp is adapted for use with anincandescent electric lamp.

by a.

b is a metallic filament incandescent electric lamp (as apposed to acarbon filament lamp or electric arc lamp), 0 a mounting for the lamp 6,d an electric lead into the lamp while 6 and f represent two glasses,one 6 being blue and the other fbeing green which glasses together formthe light filter and cause the rays of light which emanate from the lamp6 and which pass through them to be given the same qualityso far ascolor matching is concerned as good day-' light taken from a northernaspect. The blue filter in its most efiective form is of a royal bluecolor which is known in the trade as Coburg blue or Bleriot blue whilethe green filteris colored by means of nickel and is known in the tradeas nickel green. lt will be obvious b the foregoing means that a,daylight lamp is obtained the quality and quantity of the light of whichis constant. The special types of electric metallic filament lamp on themarket which In this the body of the lamp is indicated are speciallysuitable are those provided with tantalum and osmium filaments. Asalternatives to metallic incandescentelectric lamps mcandescent gas orpetroleum lamps 111 which the gas or petroleum illuminates a mantle canbe used.

The present lamp has been devised to supersede the daylight lamps inwhich the source of light is an electric arc lamp and the filter glasscolored with sulfate of cop per as these lamps sufier from variousdrawbacks which are overcome by' the present invention. It is a wellknown fact that an electric arc varies in color according to the lengthof the are from a comparatively white light to a violet light so that toob tain a true daylight efl'ect the quality of the filter would havetovary with the length of the arc which'is a practical impossibility. Acarbon 'filament lamp gives 01% such a large proportion of red rays thatany filters which would prevent the passage of red rays wouldpractically obscure the lamp altogether.

The present lamp as compared. with the electric arc lamp is cheaper tomanufacture and consumes a much less amount of current. It is alsosteady and constant in the amount and quality of the light it givesoil".

I declare that what l claim is 1. In a daylight lamp, a lamp casing, asource of light and superposed blue and green light filters.

' 2. In a daylight lamp, a metallic filament incandescent electric lampand a light filter consisting of a blue and a green glass the onesuperposed over the other.

3. In a daylight lamp, a source of light and a light filter consistingof a combination of two superposed glasses the one a royal blue and theother nickel'grccn.

4. In a daylight lamp the combination with a metallic filamentincandescent electrio lamp of a light filter consisting of twosuperposed glasses the one colored royal blue and the other colorednickel green.

In testimony whereof, l afix my signature, in presence of two witnesses.

' MAX EltTZ.

Witnesses:

Hnnnnr Pmnrnnnr, Cnas. ll-lmnnar.

